1. Field of the Invention
The present invention is generally in the field of semiconductor fabrication. More particularly, the invention is in the field of semiconductor die fabrication and packaging.
2. Background Art
A semiconductor die can be surface mounted to a package substrate employed to house the die by using flip chip technology. In flip chip technology, the semiconductor die is “flipped” over so that the active surface of the die faces the package substrate. Electrical contact between the semiconductor die and the package substrate is achieved through solder bumps (also referred to simply as “bumps” in the present application) that are placed on the active surface of the semiconductor die.
In a conventional “flip chip,” each semiconductor die pad (also referred to simply as a “pad” in the present application) situated on the active surface of the die is connected to its corresponding unique bump using a pad-to-bump routing layer on the die. For complex dies with a large number of input and output data signals, clock signals, and ground and power pads, a large array of bumps is typically required on the die. However, the increasing number of bumps in the array on the semiconductor die presents some problems. For example, as the number of bumps increases, it becomes more difficult to route a connection between the pads and the bumps. As a result, multiple routing layers are typically required on the semiconductor die, which undesirably increases manufacturing cost.